Manufacture of printing-plates or surfaces for printing from



A.]. N. WALKER MANUFACTUR E 0F PRINTING PLATES 0R SURFACES FOR PRINTINGFROM.

APPLICATION FILED JAN-251198n Patented Apr. 26, 1921 3 SHEETS-SHEET I.

A. J. N. WALKER.

MANUFACTURE OF PRINTING PLATES 0R SURFACES FOR PRINTING'FROM.

APPLICATION FILED 1AN.25.I918.

Patented Apr. 26, 1921.

3 SHEETS-SHEET 2.

\lllll Ill A. J. N. WALKER.

MANUFACTURE OF PRINTING PLATES OR SURFACES FOR PRINTING FROM.APPLICATION FILED JAN, 25, 1918.

1,375,874. Patented Apr. 26,1921.

SHEETS ALFRED JAMES NEILL WALKER, OF LIVERPOOL, ENGLAND.

MANUFACTURE OF PRINTING-PLATES 0R SURFACES FOR PRINTING FROM.

Application filed January 25, 1918.

1 o all to 7mm it may concern Be it known that I, ALFRED JAMES NEILLWALKER, a subject of the King of Great Britain, residing at Liverpool,inthe county of Lancaster and Kingdom of England, have invented certainnew and useful Improvements in or Relating to the Manufacture ofPrinting-Plates or Surfaces for Printing From, of which the following isa specification.

This invention has reference to certain improvements in making printingplates from celluloid, or other similar material that can be softened byheat.

One of the difficulties experienced in the molding of warm celluloid andlike sheet material lies in the fact that gas or liquid emanates fromthe material during the process, and being trapped with perhaps some airas well, between the pressing members so that it cannot escape, itcauses stria tions or bubbles to be formed on the face of the product.

Heretofore in one method of molding warm celluloid sheet material, fluidpressure has been employed in direct contact with the surface to bemodeled thereby. This method involves practical inconveniences andmoreover gives less satisfactory results than does the process of thepresent invention. In another method rigid press plates operated at ahigh pressure were employed and the space between them containing thecelluloid and the mold was made air tight by a rubber packing. Thisspace was put in communication with a vacuum so as to withdraw any airduring the pressing process, and the mechanism was therefore somewhatcomplex. In yet another method the celluloid was subjected to pressurebetween two faces one of which was rigid or hard and the other of whichwas an air pressure bag freely deformable by the surface (6. 9. that ofa photographic carbon negative) against which it acted, thecharacteristic feature being the employment of a pressure sufficientlylow to permit such gas or liquid as comes out of the celluloidor thelike to escape laterally between any of the said surfaces and issue attheir edges into a r gion of still lower pressure. In other arrangementsthe space between the two faces (containing the celluloid) one of whichwas rigid and hard and the otherwas an air or water bag, was made tightor the best pos sible fit, and no means whatever were pro- Specificationof Letters Patent.

Patented Apr. 26, 1921.

Serial No. 213,788.

vided for withdrawing the gas or liquid which emanates from warmcelluloid.

though in one instance it was proposed (in allowing high pressure to beemployed so as to produce a celluloid plate which will take the place ofthe ordinary electroplate or stereotype for printing letter press,pictures, posters, paper hangings and so on, will allow the gas orliquid that emanates from the warm celluloid to escape. By celluloid Imean not only celluloid itself, but any material which is similar tocelluloid in that when warmed and pressed it exudes gas and liquid.

My method consists in forming a matrix laying the same on the hollowtable of a press, providing in connection with the follower. of thepress a recess in its face to which an inflatable mattressis applied,laying on the matrix a sheet of celluloid or the like, then bringing theinflatable mattress face of the follower toward the table so that whilethe mattress will lie against the sheet which slightly enters into therecess in the follower the rigid margins of the table and follower willbe spaced apart or leave clear passages between them to allow any orliquid coming out of the sheet to escape, admitting hot fluid underpressure into the hollow chamber in the press table to warm the matrixand soften the sheet, inflating the mattress with air under pressure topress the sheet into the matrix and finally releasing the pressure andchargingthe chamber with cooling fluid to harden the sheet. By thismethod the mattress will. impact against the sheet while the rigidmargins of the table and follower will be spaced apart or leave clearpassages between them to allow such gas or liquid as comes out of thesheet to escape laterally through the passages between the table and Vfollower, and also any air between the mattrees and sheet will be urinenof" therethrough when the nr l am however aware that prior to thisinvention been prov hollow chambers which re ch hot fluid to i sequentlywits a cooling;- T

The matrix itself is produced in the iollowing manner. The type,engraved plate or other surface to be printed from is so n ill) by thecompositor in the usual way, and a. thin sheet or lead, vul anite, oriiber is im pressed upon the face of the term so as to produce a matrix.This is etl'ected by a matrix roll' machine, mangle or p wherein theform is brought into contact with the sheet of lead or other materialand is impressed thereinto, so that an exact facsimile or the printingsurface (set up by the compositor) is produced and forms the inatrn Thisma '1; cons n a mold the printing plate is made.

In order that my invention and the manner of pertorining:- the same maybe prope understood and the improvements as co 1- pared with knownapparatus may be diilerentiated T will now describe the manner ofcarrying my invention ct erence being had to the appenc :l ings, inwhich 19' ;u l is vertical cross section of the press, Fin. 2 thereof,and 3 is anenlarged vertical sectional view talrni th l the follower,showi ,he tering the recess in the tolloweix In these drawings it is thetable or bed of the press and B the head, platen or follower, which isoperated mechanically from the crank shaft 0 so that the heat can bebrought toward the table A by turning the hand wheel D the latteroperating the cranlr shaft through the gear wheels E and F.

The table A is provided with a recess with inclosing sides to receivethe ma G, and the head or follower B of the press is either recessed toreceive the inflatable szclr or mattress or the equivalent rrangementmay be provided namely providing the follower with a recess to themargin oi? which an india rubber diaph agm is attached so as to term amattress The table or bad it or the press has a hollow chamber 1 in itinto which steam can be injected through the pipe J for heating thematrix Si or into which cold air or other fluid can be driven throughthe pipe 1 for cooling. This cha1nher I is also provided with a steamsafety valve L which will automatically open to permit steam to escapeshould the pressure exceed a given limit. A release or exhaust valve Mfor steam is also provided. An air pressure pipe N from the air pumppasses into the head B of the press to the can is provided also with anair pressure release valve and the press is provideo with air pressure,steam pressure, and safety valve air pressure gages P Q, and

In operation the matrix Sr is laid in the recess in the table A, thesheet 01 celluloid S or other analogous material is applied, and thesteam through the pipe J is now turned on so as to heat the matrix Grand the celluloid sheet laid thereon. The inflatable mattress iace ofthe follower is brought toward the table so that the mattress H will lieagainst the sheet S which enters slightly into the recess in thefollower so that the s oi? the recess lie closely all around thecelluloid sheet thus holding the celluloid sheet in position, and yetallow of any air or any gas or liquid between the celluloid sheet andthe matrix to escape laterally at the edges of the sheet because thereis no tight clamping olf the inflatable mattress tace of the pressagainst the table, there being in fact a clear open space T between theeration and pumps air through pipe N into the mattress H and compressesit therein and pressure is maintained in the mattress for just so longas it is necessary to cause the surtace of the celluloid sheet to bemolded on the matrix. The air pump is now stopped and the steam shutoil, and cooling fluid is injected into the table or base A or the pressthrough the pipe K so as to cool the matrii and harden the sheet. Thehead B and table A of the press are separated and the molded sheet ofcelluloid is taken out and (when mounted on a block to make it typehigh) is used as a surface for printing from in the operation describedthe rubber face of the mattress presses the celluloid sheet on to thematrix by which a replica oi the matrix is produced in relief orint-apglio on the celluloid sheet. The celluloid is forced into all theinterstices or depressions in tile matrix i is molded in such manner toproduce a plate without striations or bubbles lfor printingletter-press, pictures, posters, paper hangings and so on.

My improved printing plates can of course be m de ilat in which. case adot matrizt is used to mold them, r they can be made of curvilinearshape as required for ro- V laid upon the matrix will partially enterthe 1917, in the presence of two subscribing witrecess below themattress while permitting nesses.

the gas or liquid between the sheet and the ALFRED JAMES "BILL WALKERmatrix to escape through the space between 5 the table and the follower.Witnesses:

In Witness whereof, I have hereunto G. C. DYMOND,

signed my name this 21st day of December JOHN MCLAOHLAN.

